Grape variety named Marroo Seedless

ABSTRACT

A new and distinct variety of grapevine named Marroo Seedless having the characteristics of large, crisp and seedless berries with a pleasant, sweet taste, a uniform bunch shape; good vigor and production and the formation of large black berried seedless table grapes without the application of gibberellic acid to enhance berry size.

The present invention comprises a new and distinct cultivar of grape,known by the cultivar name Marroo Seedless.

The new variety is the result of the following cross, CarolinaBlackrose×Ruby Seedless made at the CSIRO Division of Horticulture.

The objectives in breeding this new variety were to combine the highproductivity, large berry, good eating qualities and disease resistanceof Carolina Blackrose with the seedless character, high vigour andproductivity of Ruby Seedless.

It was selected from a progeny of 50 seedlings planted at the researchstation of the CSIRO Division of Horticulture, Merbein, Victoria,Australia in 1978. The new variety was then asexually reproduced fromcuttings taken from the original seedling selection in winter 1982 andtested in field trials at the Merbein site, under the number, MS23-7.The variety was further tested at a regional level by State Departmentsof Agriculture and on selected grower properties. The unique features ofthe new variety have been retained.

Marroo Seedless has not been observed under all possible environmentalconditions. The phenotype may vary significantly with variations inenvironment such as temperature, light intensity and day length.

The following traits have been repeatedly observed and are determined tobe basic characteristics of Marroo Seedless, which in combinationdistinguish Marroo Seedless as a new and distinct cultivar.

(1) Large, black, crisp and seedless berry with a pleasant sweet taste;

(2) A uniform bunch shape;

(3) Good vigour and production;

(4) Production of large, black-berried seedless table grapes withoutapplication of gibberellic acid to enhance berry size.

The variety ripens early mid-season, about two weeks before its seedlessparent, Ruby Seedless and is best adapted for culture under the sametype of soil and climatic conditions.

The accompanying photographic drawings illustrate characteristics of theMarroo Seedless wherein,

FIG. 1 illustrates a typical shoot tip of this variety,

FIG. 2 illustrates both the upper and lower surfaces of typical leaves,

FIG. 3 illustrates a typical cluster of the new variety, without bunchtrimming, and

FIG. 4 illustrates a typical cluster of the new variety, after bunchtrimming.

PLANT CHARACTERISTICS

The distinctive varietal characteristics of the novel plant describedbelow in detail were observed during the first fruiting season andthereafter in trial plots at Merbein, Victoria, Australia, without theapplication of gibberellic acid.

Vine: Similar vigour to Ruby Seedless, with slender straight trunks,foliage canopy medium permitting uniform colouring of the fruit. Budburst medium, at the same time as Ruby Seedless, leaf-fall medium,autumn coloration yellow-red.

Shoot-tip: (10"-12") Summit open, yellow-green, tinged bronze glabrous,shiny. First flat leaf 5-lobed, very shiny surface, lightly bronzed,tips shiny.

Shoot: Semi-erect habit, green with red stripes between nodes, nodesgreen vigorous, tendrils discontinuous, strong, bearing inflorescencesat the 4th, 5th and 6th node, inflorescence medium width with strong,short peduncle, flower hermaphrodite, stamens diverging, filamentsrigid.

Canes: Numerous canes, open, good wood maturity, reddish brown, smoothsurface, lenticels absent, elliptic cross section, buds medium,"pointed" and sealed.

Leaf: Medium in size, short, pentagonal, upper surface medium green,hairless, involute, medium blistering on upper surface, teeth very long,straight sided, medium width petiolar sinus open, vee shaped, upper leafsinuses slightly overlapping, the slightly reddened petiole shorter thanmain vein, no prostrate or erect hairs, resistant to downy mildew.

Cluster: Large, average 0.8-1.0 kg, 25 cm overall length from point ofattachment, width 18 cm, peduncle short, 4.0 cm from attachment to firsttendril branch, loose.

Berry: Medium, mean weight of 4.5-6.0 g; uniform in size, shortelliptic, circular cross section; skin colour blue/black and uniform,medium bloom; flesh firm and juicy, not coloured, neutral flavour,expressed juice is clear; seedless with occasional lignified rudimentaryseed; pedicel attachment to berry strong.

I claim:
 1. The new and distinct variety of grapevine substantially asherein shown and described.